Marshall was removed during the second quarter of Thursday night's game against the Dallas Cowboys.
At the end of a 15-yard pass play, Marshall's back absorbed contact from Cowboys defensive back Barry Church's knee. Marshall lay on the field in pain for several minutes and was seen leaving Soldier Field in an ambulance.
Bears coach Marc Trestman commented on the injury after the game.
"It’s scary any time that a guy goes down and is laying on the ground," Trestman said. "We all worry for him. We’ll see, and we’re hopeful it’s nothing too serious. But at this point he is under evaluation."
Marshall has also missed time this season because of ankle issues.
Trestman was asked Friday who would start in place of Marshall against New Orleans. "We'll see that as we work through the week," he said.